I have been reading about chrysanthemums being used in pu erh and being popular in Hong Kong and what not. Now, I imagine that if I want to use chrysanthemums with my pu erh gong fu style that I just add the blossoms, and its bussines as usual, but I figured it wouldn't hurt to ask as well.

This is just a guess, but I think that the flowers would need to be dried first. I once tried adding fresh mint leaves to a brew, and the results were, well, quite terrible.

I don't have any experience with herbal teas, but I assume that steeping times are widely varied between different plants. If whole blossoms don't work well, perhaps adding smaller pieces of the blossoms would allow it to infuse more completely by increasing the amount of surface area on the flowers.

I think it would be an interesting experiment-- if you try it, let us know how it turns out!

This is commonly called Guk Po Cha (pronounced gook po cha) and it has an interesting flavour. If you buy your mums from a Chinese herb shop they will be very flavourful and quite small and will steep well. In most recipes, there are a relatively small amount of mums to the pu-erh pot. Chado (www.chadotea.com)in LA sells a nice blend that is smooth and inexpensive.
I wouldn't use your very best pu-erh to blend since the mum flavour is pronounced.
Crysanthmum has a cooling effect and is good for internal heat conditions (Chinese medicine). It's more likely satisfying in the heat of the summer.
I've seen a great deal more of it ordered with dim sum in the warmer months.
Happy sipping!
Shen